Year	% of total
1990	57.83826452369841
1991	56.045031984949475
1992	48.571890316989005
1993	48.957073774809615
1994	50.32894786371647
1995	50.08216117035937
1996	50.95002503639248
1997	49.09186247709593
1998	46.33734543503144
1999	46.23124648252049
2000	45.129217257602484
2001	44.228947796107164
2002	46.04078091643867
2003	48.320645466407164
2004	49.40069819538714
2005	50.99248582427643
2006	52.12874946283618
2007	50.229122046534755
2008	54.64091672059816
2009	52.06612096318591
2010	54.20610955866313
2011	55.980836584749035
2012	56.35772158764165
2013	54.12011787263757
2014	53.905417040641616
2015	53.86061936815111
2016	52.60004316275137